Northwest Airlines Flight 2
A Lockheed 14H similar to the accident aircraft
|Site||Gallatin County, near Bozeman, Montana, USA|
|Aircraft type||Lockheed Model 14H Super Electra|
|Flight origin||Spokane Airport, Washington|
|Stopover||Butte Airport (BTM/KBTM)|
|1st stopover||Billings Municipal Airport (BIL/KBIL)|
|Destination||Chicago-Midway Airport (MDW/KMDW)|
Northwest Airlines Flight 2 was a Lockheed Super Electra aircraft, registration NC17388, which crashed into the Bridger Mountains about 12 miles (19 km) northeast of Bozeman, Montana, on January 10, 1938. All ten on board were killed in the accident, which was the first fatal crash of a Northwest Airlines aircraft or a Lockheed Super Electra.
Flight 2 was en route from Seattle, Washington to Chicago, Illinois, with intermediate stops at Spokane, Washington, Butte, Montana, and Billings, Montana. The flight had just left Butte and was flying over Belgrade, Montana when it diverted to the north to avoid a dust storm over Bozeman Pass. The first officer contacted the Northwest Airlines radio operator at 3:05 PM Mountain Standard Time to advise that Flight 2 had reached the cruising altitude of 9,000 feet at 2:53 PM. Ground witnesses reported that as it passed over the Bridger Mountain range (which at the point the aircraft passed over reaches a height of approximately 8,500 feet MSL) the aircraft immediately dropped, went into a stall, glided for a short time, then spun into the ground. The wreckage burst into flames. All aboard died immediately.
Investigators with the Civil Aeronautics Authority, a predecessor organization of both the FAA and the NTSB, determined that both vertical fins and both rudders were missing from the twin-tailed aircraft. They believed that the empennage had failed due to flutter. Weather reports from surrounding communities as well as the existence of the dust storm in Bozeman Pass led investigators to believe that the aircraft likely encountered severe to extreme turbulence which may have initiated the flutter.
Within 24 hours of the accident, the United States Department of Commerce (the governing authority of the CAA) ordered that all Lockheed Super Electras be immediately grounded and that tests be performed to confirm that the figures obtained in the aircraft's original vibration tests were accurate. It was discovered that the machine used by Lockheed (and authorized by the Department of Commerce) to measure the natural vibration periods of the component parts of the aircraft had given Lockheed engineers misleading results. The Department ordered that the rudders of all Super Electras be modified so as to eliminate the possibility that flutter would cause an in-flight break-up.
Northwest had been the first United States airline to take delivery of the Super Electra, but sold most of its remaining Electra fleet in 1939 after three subsequent accidents called the airworthiness and commercial potential of the aircraft into question. One Electra crashed in California while in the process of being delivered to the airline. The second, Flight 4, crashed in Billings, Montana after the pilot stalled the aircraft on takeoff. The third, Flight 1, crashed near Miles City, Montana after a design and manufacturing error allowed an intense fire to develop in the cockpit.